They are looking for a substitute for oil
If coal were used at the same rate as oil, for example using coal liquefaction, then it wouldn't last any longer than oil. In other words, the world has far less than 100 years of fossil fuel reserves remaining, and the current technological base cannot be sustained.
Of course things have changed rather significantly in the last 100 years... but don't ask me to put a positive spin on that retort, because I don't see a positive spin on this particular situation.